Use this party wall cost calculator to work out what your party wall surveyor fees are likely to be in London before you commit to your build. Fees under the Party Wall etc. Act 1996 vary hugely depending on one thing above all: how your neighbour responds to your notice.
How the Party Wall Cost Calculator Works
Once you serve valid party wall notices, your adjoining owner has three options, and each has a very different price tag:
- Neighbour consents in writing – no surveyors are appointed, so your surveyor cost is £0. We still recommend a schedule of condition to protect both parties.
- Agreed surveyor – one surveyor acts impartially for both owners and produces the award. Typical London fee: £700-£1,200.
- Two surveyors – each owner appoints their own surveyor. The building owner normally pays both fees: typically £1,500-£3,500 in total.
- Basement projects – excavation alongside neighbouring foundations demands more detailed checking, so budget £2,500-£5,000+ where two surveyors are involved.
Party Wall Fee Calculator Matrix (Typical London Costs)
Find your project type in the left-hand column, then read across to the scenario that applies to you.
| Project type | Neighbour consents | Agreed surveyor | Two surveyors |
|---|---|---|---|
| Loft conversion (beams into party wall) | £0 | £700-£950 | £1,500-£2,200 |
| Rear extension (works to wall and/or excavation) | £0 | £750-£1,100 | £1,600-£2,800 |
| Basement conversion or underpinning | £0 | £900-£1,200 | £2,500-£5,000+ |
| New wall at the boundary (line of junction) | £0 | £700-£900 | £1,400-£2,000 |
Figures are per adjoining owner. A mid-terrace house with neighbours on both sides may double these ranges, which is why the full costs of the party wall process should be budgeted early.
What Moves the Cost Up or Down?
- Number of adjoining owners – each neighbouring freeholder and long leaseholder must be served, and each can appoint a surveyor.
- How the neighbour responds – consent is free; dissent triggers surveyor appointments and a formal party wall award.
- Depth of excavation – foundations within 3 or 6 metres of a neighbouring structure engage the 3 and 6 metre rule and usually require engineering drawings, adding review time.
- The adjoining owner’s surveyor – the building owner generally pays their reasonable fee, and hourly rates in central London are higher.
- Complexity and access – flats, mansion blocks, listed buildings and difficult access all extend the schedule of condition inspection.
Party Wall Cost Calculator FAQs
Who pays the party wall surveyor fees?
Under the Act, the building owner undertaking the works normally pays all reasonable surveyor fees, including the adjoining owner’s surveyor. Costs can be apportioned differently where works benefit both owners, such as repairs to a shared wall.
Can my neighbour run up unlimited fees?
No. Fees must be reasonable, and if the two appointed surveyors cannot agree them, the third surveyor can determine the matter. See our guide to party wall disputes and resolution.
Is a party wall award always needed?
Only if an adjoining owner dissents or fails to respond within 14 days. Written consent to a valid notice means no award is required, though records of condition remain sensible.
Are these fees fixed?
We work on fixed fees wherever possible, agreed before appointment, so you are never exposed to open-ended hourly billing on our side.
Every project is different, so treat this calculator as a guide. For an exact fixed quote for your address, request a party wall quote today or contact us and one of our RICS surveyors will confirm your costs the same day.
Speak to a RICS party wall surveyor now: call 0204 579 8270 or request a free consultation – same-day advice across every London borough.